What is your account type - POP or IMAP?

POP I guess. Hotmail and gmail. This is same as always (was the same ẃith WLM that I was using until recently). It was why I never really understood the point of comments like "check your spam folder". I could always see whether there had anything been added without checking.

With a POP account Thunderbird does not get the messages which have already been classified as spam on the server. That's probably the reason why you don't see new spam messages in your local junk folder. So you'll need to login to your account via webmail and check the spam folder on the server.

But if I click on the junk/spam folder within TB it shows everything same as with the inbox, sent etc. I don't need to log in via web mail. The problem is that TB does not "ask" for the new messages automatically same as it does with the inbox and does not highlight the junk folder as having x-many new messages, also as it does with inbox.

If it is the way TB has been set up, then I believe it should definitely be changed. Having lived with WLM for several years, I know it is not a technical issue (or at least it wasn't for WLM), but rather a conscious decision or an oversight.

Either way, it is so much more convenient to be automatically warned about sthng having been classified as junk, so that you can just click on only the relevant junk folders and make certain you are not missing legitimate mail.

Please add the troubleshooting information to your post To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

Thank you. Here it goes:

 Application Basics

   Name: Thunderbird
   Version: 45.1.1
   User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.1
   Profile Folder: Show Folder

             (Local drive)
   Application Build ID: 20160526140950
   Enabled Plugins: about:plugins
   Build Configuration: about:buildconfig
   Memory Use: about:memory

 Mail and News Accounts
   account1:
     INCOMING: account1, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account2:
     INCOMING: account2, , (none) Local Folders, plain, passwordCleartext

   account3:
     INCOMING: account3, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account4:
     INCOMING: account4, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account5:
     INCOMING: account5, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account6:
     INCOMING: account6, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account7:
     INCOMING: account7, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account8:
     INCOMING: account8, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account9:
     INCOMING: account9, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account10:
     INCOMING: account10, , (imap) mail.uoa.gr:993, SSL, passwordCleartext
     OUTGOING: , smtp.uoa.gr:465, SSL, passwordCleartext, true

   account11:
     INCOMING: account11, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account12:
     INCOMING: account12, , (imap) imap-mail.outlook.com:993, SSL, passwordCleartext
     OUTGOING: , smtp-mail.outlook.com:587, alwaysSTARTTLS, passwordCleartext, true

   account13:
     INCOMING: account13, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account14:
     INCOMING: account14, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account15:
     INCOMING: account15, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account16:
     INCOMING: account16, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account17:
     INCOMING: account17, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account18:
     INCOMING: account18, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

   account19:
     INCOMING: account19, , (imap) imap.gmail.com:993, SSL, OAuth2
     OUTGOING: , smtp.gmail.com:465, SSL, OAuth2, true

 Crash Reports

 Extensions
   ImportExportTools, 3.2.4.1, true, {3ed8cc52-86fc-4613-9026-c1ef969da4c3}
   Lightning, 4.7.1.1, true, {e2fda1a4-762b-4020-b5ad-a41df1933103}

 Important Modified Preferences

   Name: Value

     browser.cache.disk.capacity: 358400
     browser.cache.disk.filesystem_reported: 1
     browser.cache.disk.smart_size_cached_value: 358400
     browser.cache.disk.smart_size.first_run: false
     browser.cache.disk.smart_size.use_old_max: false
     dom.apps.reset-permissions: true
     extensions.lastAppVersion: 45.1.1
     font.name.monospace.el: Consolas
     font.name.monospace.x-cyrillic: Consolas
     font.name.monospace.x-unicode: Consolas
     font.name.monospace.x-western: Consolas
     font.name.sans-serif.el: Calibri
     font.name.sans-serif.x-cyrillic: Calibri
     font.name.sans-serif.x-unicode: Calibri
     font.name.sans-serif.x-western: Calibri
     font.name.serif.el: Cambria
     font.name.serif.x-cyrillic: Cambria
     font.name.serif.x-unicode: Cambria
     font.name.serif.x-western: Cambria
     font.size.fixed.el: 14
     font.size.fixed.x-cyrillic: 14
     font.size.fixed.x-unicode: 14
     font.size.fixed.x-western: 14
     font.size.variable.el: 17
     font.size.variable.x-cyrillic: 17
     font.size.variable.x-unicode: 17
     font.size.variable.x-western: 17
     mail.openMessageBehavior.version: 1
     mail.winsearch.firstRunDone: true
     mailnews.database.global.datastore.id: 32214733-cdbf-4a6d-a902-22023df6c31
     network.cookie.prefsMigrated: true
     network.predictor.cleaned-up: true
     places.database.lastMaintenance: 1467641983
     places.history.expiration.transient_current_max_pages: 57715
     plugin.importedState: true
     print.printer_HP_Color_LaserJet_2550_PS.print_bgcolor: false
     print.printer_HP_Color_LaserJet_2550_PS.print_bgimages: false
     print.printer_HP_Color_LaserJet_2550_PS.print_evenpages: true
     print.printer_HP_Color_LaserJet_2550_PS.print_footercenter:
     print.printer_HP_Color_LaserJet_2550_PS.print_footerleft: &PT
     print.printer_HP_Color_LaserJet_2550_PS.print_footerright: &D
     print.printer_HP_Color_LaserJet_2550_PS.print_headercenter:
     print.printer_HP_Color_LaserJet_2550_PS.print_headerleft: &T
     print.printer_HP_Color_LaserJet_2550_PS.print_headerright: &U
     print.printer_HP_Color_LaserJet_2550_PS.print_in_color: true
     print.printer_HP_Color_LaserJet_2550_PS.print_margin_bottom: 0.393750011920929
     print.printer_HP_Color_LaserJet_2550_PS.print_margin_left: 0.393750011920929
     print.printer_HP_Color_LaserJet_2550_PS.print_margin_right: 0.393750011920929
     print.printer_HP_Color_LaserJet_2550_PS.print_margin_top: 0.393750011920929
     print.printer_HP_Color_LaserJet_2550_PS.print_oddpages: true
     print.printer_HP_Color_LaserJet_2550_PS.print_orientation: 0
     print.printer_HP_Color_LaserJet_2550_PS.print_reversed: false
     print.printer_HP_Color_LaserJet_2550_PS.print_scaling: 1,00
     print.printer_HP_Color_LaserJet_2550_PS.print_shrink_to_fit: true
     privacy.donottrackheader.enabled: true

 Graphics

     Adapter Description: Intel(R) HD Graphics 4000
     Vendor ID: 0x8086
     Device ID: 0x0162
     Adapter RAM: Unknown
     Adapter Drivers: igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32
     Driver Version: 10.18.10.4061
     Driver Date: 12-18-2014
     Direct2D Enabled: false
     DirectWrite Enabled: false (6.2.9200.17461)
     ClearType Parameters: ClearType parameters not found
     WebGL Renderer: Google Inc. -- ANGLE (Intel(R) HD Graphics 4000 Direct3D11 vs_5_0 ps_5_0) -- OpenGL ES 2.0 (ANGLE 2.1.0.316930d51ea9)
     GPU Accelerated Windows: 0

     AzureCanvasBackend: skia
     AzureSkiaAccelerated: 0
     AzureFallbackCanvasBackend: cairo
     AzureContentBackend: cairo

 JavaScript

 Incremental GC: 1

 Accessibility

   Activated: 0
   Prevent Accessibility: 0

 Library Versions

     Expected minimum version
     Version in use

     NSPR
     4.12
     4.12

     NSS
     3.21.1 Basic ECC
     3.21.1 Basic ECC

     NSS Util
     3.21.1
     3.21.1

     NSS SSL
     3.21.1 Basic ECC
     3.21.1 Basic ECC

     NSS S/MIME
     3.21.1 Basic ECC
     3.21.1 Basic ECC

POP I guess.

There isn't a single POP account.

Does the problem affect any particular (IMAP) account? If so, which one? Or Outlook.com accounts only?

Sorry, got the terms mixed up. Just clicked on gmail accounts and there was one junk e-mail in one of them that I only saw (and the folder got bolded and showed "(1)") only after Iclicked on it. So it is the same for both hotmail and gmail.

right click the account in the folder pane and select settings. In server setting for the account, make sure "Allow immediate server notifications when new messages arrive" is selected

Thanks. Already checked in all accounts' settings.

I may have found it!

R-click on junk folder > properties > check "when getting new messages, check this folder".

Will update after checked.

Nope. Still the same...

Please post a screenshot of the folder pane with all folders visible (expanded) for one of the affected accounts. http://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem

While I was saving the screenshot 2 junk folders turned blue with "(1)" next to them. So maybe junk folders are checked some time after inboxes? Will monitor and update.

In the meantime here is the screenshot.

So far Hotmail accounts have been sporadically showing incoming junk. It does appear though that the check is not done at the same time as the inbox, which is totally OK, just so long as junk folders are regularly checked and we are notified of junk mail without having to manually go into each junk folder to check. Will go on checking (also f/ the gmail accounts) and update.

Are you using antivirus?

You have quite a lot of accounts all with the same two providers and it may just not have enough time to service all the folders in all your accounts before having to start over again, particularly if anti-virus scanning of your folders is also taking place in the background.

With accounts provided by multiple providers, Thunderbird is probably able to talk to several servers concurrently. If several of your accounts are all on one provider, I wonder if the server expects you to queue for each account to be accessed serially, one after the other. And if there is any pecking order hierarchy, maybe Junk and Spam are some way down the priorities list.

So far it appears to be a question of time delay, which is not a problem. All I care about is that eventually I get to see all folders having received new junk mail without having to manually click on them one by one.

Only thing I still need to check is whether it also works with gmail after the last settings change I described. I have so far not had a notification.